The ability to reduce the surface tension of liquid compositions, particularly aqueous compositions, is of great importance in a wide variety of compositions including solutions, dispersions, gels, emulsions, latex compositions, and the like. Such compositions are used in a wide range of applications including paints and other coatings, stains and other coloring agents, ink compositions, oil and gas recovery compositions, steam assisted gravity drainage compositions, chemical flooding compositions, cosmetics, foods, nutriceuticals, health care products, cleaning products, etching compositions, agrochemicals, or the like.
It is well known in the art that so-called Gemini surfactants, which are surfactants with multiple hydrophobic tails and multiple hydrophilic heads, or Gemini-like surfactants exhibit superior properties compared to those of analogous conventional surfactants. See, e.g., Gemini Surfactants: Synthesis, Interfacial and Solution-Phase Behavior, and Applications, Vol. 117, Zana, R.; Xia, J., Eds.; Marcel Dekker: New York, 2004. Furthermore, it is also well known in the art that increasing branching in a hydrophobic tail significantly improves wetting properties of a surfactant. See, e.g., Rosen, M. J. Surfactants and Interfacial Phenomena, 3rd ed.; John Wiley & Sons, Inc.; Hoboken, N. J., 2004; pp. 243-277.
Important surfactant performance characteristics include equilibrium surface tension properties, dynamic surface tension properties, wetting properties, foaming properties, and the like. Equilibrium surface tension is important when a system is at rest. Dynamic surface tension is a fundamental property which measures the ability of a surfactant to perform under high speed application conditions. Many nonionic surfactants may have acceptable equilibrium surface tension properties, but demonstrate poor dynamic surface tension properties. Many nonionic surfactants also tend to be foamy and make compositions too susceptible to foaming, which can be undesirable in many applications. The importance of improving equilibrium, dynamic, wetting and foaming performance is well-appreciated in the art.
Accordingly, there is a strong demand for nonionic surfactants that provide not only strong equilibrium surface tension properties but also strong dynamic surface tension properties and strong wetting properties with a reduced tendency to cause foaming.